Energy Savings

Individual Temperature Control (many small zones) prevents over cooling or over heating when spaces are unoccupied. This is possible using a VAV Box per office, but typically is not an economically viable solution. A Therma-Fuser diffuser system offers many small zones at a similar installed first cost to a typical VAV Box system with a single thermostat for three to six rooms.

Lower Turndown than a VAV Box and Elimination of Total Pressure Drop Over the Box are both related to the limitation of air flow measurement with a VAV box – typically by using a differential pressure sensor. For this measurement to be accurate, a minimum air velocity must be maintained resulting in a VAV box operating with a 25-30% minimum flow and a 0.4”wg/100 Pa total pressure drop.

Therma-Fuser diffuser systems do not have a velocity limitation because pressure independence is achieved by measuring only static pressure. Since a minimum air velocity is not required, any static pressure damper may be oversized to minimize the pressure drop without the penalty of increasing minimum flow and the Therma-Fuser diffuser system can operate at minimum flow of 10% or less.

An All Low-Pressure Duct System further reduces the total system pressure, further reducing the required fan horsepower and energy used. Unlike the medium pressure VAV Box, the Therma-Fuser diffuser is a low-pressure device and only requires a low-pressure supply. The following example illustrates the possible savings from a Therma-Fuser diffuser system: By eliminating the pressure drop over the box and running an all low-pressure system, there is a 33% reduction in fan energy with a Therma-Fuser diffuser system.